feat(filter-query): add RelatedAttrFilterQuery for relational filters

Author: jaredcnance

src/JsonApiDotNetCore/Internal/Query/AttrFilterQuery.cs

@@ -1,51 +1,39 @@
-using System;
 using System.Linq;
 using JsonApiDotNetCore.Models;
 using JsonApiDotNetCore.Services;
 
 namespace JsonApiDotNetCore.Internal.Query
 {
-  public class AttrFilterQuery
-  {
-    private readonly IJsonApiContext _jsonApiContext;
-
-    public AttrFilterQuery(
-        IJsonApiContext jsonApiCopntext,
-        FilterQuery filterQuery)
-    {
-      _jsonApiContext = jsonApiCopntext;
-
-      var attribute = GetAttribute(filterQuery.Key);
-
-      if (attribute == null)
-        throw new JsonApiException("400", $"{filterQuery.Key} is not a valid property.");
-
-      FilteredAttribute = attribute;
-      PropertyValue = filterQuery.Value;
-      FilterOperation = GetFilterOperation(filterQuery.Operation);
-    }
-
-    public AttrAttribute FilteredAttribute { get; set; }
-    public string PropertyValue { get; set; }
-    public FilterOperations FilterOperation { get; set; }
-
-    private FilterOperations GetFilterOperation(string prefix)
-    {
-      if (prefix.Length == 0) return FilterOperations.eq;
-
-      FilterOperations opertion;
-      if (!Enum.TryParse<FilterOperations>(prefix, out opertion))
-        throw new JsonApiException("400", $"Invalid filter prefix '{prefix}'");
-
-      return opertion;
-    }
-
-    private AttrAttribute GetAttribute(string propertyName)
+    public class AttrFilterQuery : BaseFilterQuery
     {
-      return _jsonApiContext.RequestEntity.Attributes
-          .FirstOrDefault(attr =>
-              attr.InternalAttributeName.ToLower() == propertyName.ToLower()
-      );
+        private readonly IJsonApiContext _jsonApiContext;
+
+        public AttrFilterQuery(
+            IJsonApiContext jsonApiCopntext,
+            FilterQuery filterQuery)
+        {
+            _jsonApiContext = jsonApiCopntext;
+
+            var attribute = GetAttribute(filterQuery.Key);
+
+            if (attribute == null)
+                throw new JsonApiException("400", $"{filterQuery.Key} is not a valid property.");
+
+            FilteredAttribute = attribute;
+            PropertyValue = filterQuery.Value;
+            FilterOperation = GetFilterOperation(filterQuery.Operation);
+        }
+
+        public AttrAttribute FilteredAttribute { get; set; }
+        public string PropertyValue { get; set; }
+        public FilterOperations FilterOperation { get; set; }
+
+        private AttrAttribute GetAttribute(string propertyName)
+        {
+            return _jsonApiContext.RequestEntity.Attributes
+                .FirstOrDefault(attr =>
+                    attr.InternalAttributeName.ToLower() == propertyName.ToLower()
+            );
+        }
     }
-  }
 }

src/JsonApiDotNetCore/Internal/Query/BaseFilterQuery.cs

@@ -0,0 +1,18 @@
+using System;
+
+namespace JsonApiDotNetCore.Internal.Query
+{
+    public class BaseFilterQuery
+    {
+        protected FilterOperations GetFilterOperation(string prefix)
+        {
+            if (prefix.Length == 0) return FilterOperations.eq;
+
+            FilterOperations opertion;
+            if (!Enum.TryParse<FilterOperations>(prefix, out opertion))
+                throw new JsonApiException("400", $"Invalid filter prefix '{prefix}'");
+
+            return opertion;
+        }
+    }
+}

src/JsonApiDotNetCore/Internal/Query/FilterQuery.cs

@@ -12,5 +12,6 @@ public FilterQuery(string key, string value, string operation)
         public string Key { get; set; }
         public string Value { get; set; }
         public string Operation { get; set; }
+        public bool IsAttributeOfRelationship => Key.Contains(".");
     }
 }

src/JsonApiDotNetCore/Internal/Query/RelatedAttrFilterQuery.cs

@@ -0,0 +1,51 @@
+using System.Linq;
+using JsonApiDotNetCore.Models;
+using JsonApiDotNetCore.Services;
+
+namespace JsonApiDotNetCore.Internal.Query
+{
+    public class RelatedAttrFilterQuery : BaseFilterQuery
+    {
+        private readonly IJsonApiContext _jsonApiContext;
+
+        public RelatedAttrFilterQuery(
+            IJsonApiContext jsonApiCopntext,
+            FilterQuery filterQuery)
+        {
+            _jsonApiContext = jsonApiCopntext;
+
+            var relationshipArray = filterQuery.Key.Split('.');
+
+            var relationship = GetRelationship(relationshipArray[0]);
+            if (relationship == null)
+                throw new JsonApiException("400", $"{relationshipArray[0]} is not a valid relationship.");
+
+            var attribute = GetAttribute(relationship, relationshipArray[1]);
+            if (attribute == null)
+                throw new JsonApiException("400", $"{relationshipArray[1]} is not a valid attribute on {relationshipArray[0]}.");
+
+            FilteredRelationship = relationship;
+            FilteredAttribute = attribute;
+            PropertyValue = filterQuery.Value;
+            FilterOperation = GetFilterOperation(filterQuery.Operation);
+        }
+
+        public AttrAttribute FilteredAttribute { get; set; }
+        public string PropertyValue { get; set; }
+        public FilterOperations FilterOperation { get; set; }
+        public RelationshipAttribute FilteredRelationship { get; private set; }
+
+        private RelationshipAttribute GetRelationship(string propertyName)
+        {
+            return _jsonApiContext.RequestEntity.Relationships
+              .FirstOrDefault(r => r.InternalRelationshipName.ToLower() == propertyName.ToLower());
+        }
+
+        private AttrAttribute GetAttribute(RelationshipAttribute relationship, string attribute)
+        {
+            var relatedContextExntity = _jsonApiContext.ContextGraph.GetContextEntity(relationship.Type);
+            return relatedContextExntity.Attributes
+              .FirstOrDefault(a => a.InternalAttributeName.ToLower() == attribute.ToLower());
+        }
+    }
+}